A crescente degradação de ecossistemas tornam necessários inúmeros esforços para recuperá-los. A ecologia da restauração é uma ciência que vem crescendo, buscando suporte e apoiando as bases da ecologia teórica. O papel das áreas restauradas na manutenção da biodiversidade é ainda incerto, mas há consenso que estas devem restabelecer os atributos ecológicos. A escolha de bons indicadores ecológicos é crucial para avaliar a evolução dessas áreas. A análise da vegetação é um bom indicador, por ser possível utilizar métodos simples de execução e apresentar respostas rápidas às condições (bióticas e abióticas), fornecendo, por exemplo, informação dos agentes dispersores na área e das características das espécies que compõe a comunidade. Através dessas informações é possível inferir se a área é visitada por animais e como ocorre o processo sucessional. A presente pesquisa consistiu na análise da vegetação de florestas em processo de restauração com idades diferentes. Foram escolhidos plantios com oito e 12 anos e um remanescente florestal. Em cada área foram alocadas 30 parcelas de 10 x 10 m, todos os indivíduos arbustivo-arbóreos (estrato arbóreo) com diâmetro a altura do peito maior ou igual a 10 cm foram amostrados, identificados e tiveram sua altura estimada. O estrato regenerante foi registrado por parcelas de 2 x 10 m alocadas no interior das parcelas (10 x 10m) onde foram amostrados e identificados indivíduos com altura maior ou igual a 50 cm e diâmetro a altura do peito menor que 10 cm. As espécies encontradas foram categorizadas em grupos funcionais (síndromes de dispersão e classes de sucessão) e origem (nativa e exótica). Para o estrato arbóreo e para o regenerante, o ecossistema de referência apresentou maior densidade, riqueza e diversidade. Diferente do ecossistema de referência, os plantios apresentaram muitos indivíduos de espécies de origem exótica, e não apresentaram muitos indivíduos das classes sucessionais clímax. Diante dos resultados talvez sejam necessárias ações de manejo adaptativo, com retirada das espécies que tem potencial invasor e enriquecimento funcional para que a evolução das áreas não seja comprometida. A avaliação da vegetação mostrou-se bom indicativo no estudo da evolução das áreas em processo de restauração. / The growing degradation of ecosystems makes it necessary the adoption of various efforts in order to restore it. Restoring ecology is a science that has been growing, seeking support and providing support to the foundations of theoretical ecology. The role of the restored areas in the maintenance of biodiversity is still uncertain; however there is consensus that they should restore the ecological attributes. The choice of good ecological indicators is crucial in order to assess the evolution of those areas. The analysis of the vegetation is a good indicator, because it enables the use of simple execution methods and because it also presents fast answers to the conditions (biotic and abiotic) providing for example, information about the dispersing agents of the area as well as the characteristics of the species that makes up the community. Through this information, it is possible to infer if the area is visited by animals and how the succession process happens. The current research consists of the analysis of the vegetation of forests in restoring process with different ages. Plantings were chosen between 8 to 12 years and a remnant forest. In each area 30 plots of 10 X 10 m were allocated, all tree species with diameter and breast height higher or the same as 10 cm were shown, identified and had their height estimated. The regenerative component was recorded in plots of 2 X 10 m allocated in the interior of the plots where they were sampled and identified the individuals with height higher than 50 cm and diameter and breast height lower than 10 cm. The species found were categorized in functional groups (dispersion syndrome and restoring guilds). The highest values of density, richness and diversity of arboreal and regeneration layers were found in the reference ecosystem. The forests in process of restoration considered in this work, unlike the reference ecosystem, presented numerous individuous of exotic species, and did not present many late-successional individuous. Results suggest that performing adaptative management actions, such as invasive species removal and functional enrichment, may be necessary for the appropriate evolution of the concerned areas. Evaluation of the vegetation was considered a good indicator to study the development of areas in process of restoration.

Fragmentation of the Atlantic forest is extensive and a major reason for biodiversity loss in the South American continent. Today only a fraction of the pre-Colombian forest cover is still left and predominantly represented by isolated fragments. In the highlands of southern Brazil the biome constitutes the eco-region Araucaria moist forest that has a unique plant composition and many endemic species. This study has focused on one small fragment of Araucaria moist forest within the state Rio Grande do Sul in southern Brazil. The study was performed as an inventory of the tree species present in the fragment to acknowledge its diversity and tree species composition. From this the origin and conservation status for the fragment could be concluded. The inventory demonstrated high species diversity for the fragment with a Shannon index of nearly 3,43. Also many similarities to natural Araucaria moist forest were evident with the occurrence of 12 of the 19 native species most represented in natural forests. A high percentage of dead trees were documented with nearly 6,5 % . Further the endemic species Dicksonia sellowiana and Nectandra megapotamica were recorded within the fragment, D. sellowiana is an endangered species in Brazil. These results indicated a fragment with natural origin as part of the mosaic composition in the eco-region rather than a result of human land use such as plantation or regrowth of agricultural land. Thus the fragment may be a remnant from the great Araucaria forest expansion occurring in the second part of the Late Holocene with an age of up to 1100 years. This study suggests that the surveyed Araucaria moist forest fragment has significant conservation status and deserves accurate conservation measures to be taken for the continuing existence of this unique and threatened eco-region.

The giant planets exhibit banded zonal jet streams that have maintained theirstructures over decades. There are long-standing questions: how deep the windstructures extend? What mechanisms generate and maintain the observed winds?Why are the wind structures so stable? To answer these questions, we performedthree-dimensional numerical simulations of the atmospheric flow using the primitiveequations.First, we use a simple Newtonian cooling scheme as a crude approach to gener-ate atmospheric latitudinal temperature differences that could be caused by latentheating or radiation. Our Jupiter-like simulations show that shallow thermal forcingconfined to pressures near the cloud tops can produce deep zonal winds from thetropopause all the way down to the bottom of the simulated atmosphere (a fewhundred bars). These deep winds can attain speeds comparable to the zonal jetspeeds within the shallow, forced layer; they are pumped by Coriolis accelerationacting on a deep meridional circulation driven by the shallow-layer eddies.Next, we explicitly include the transport of water vapor and allow condensationand latent heating to occur whenever the water vapor is supersaturated. Our simu-lations show that large-scale moist convection associated with condensation of watervapor can produce multiple zonal jets similar to those on the gas giants (Jupiterand Saturn) and ice giants (Uranus and Neptune). For plausible water abundances(3-5 times solar on Jupiter/Saturn and 30 times solar on Uranus/Neptune), oursimulations produce about 20 zonal jets for Jupiter and Saturn and 3 zonal jetson Uranus and Neptune. Moreover, these Jupiter/Saturn cases produce equatorialsuperrotation whereas the Uranus/Neptune cases produce equatorial subrotation,consistent with the observed equatorial jet direction on these planets. Sensitiv-ity tests show that the water abundance is the controlling factor; modest waterabundances favor equatorial superrotation, whereas large water abundances favorequatorial subrotation. This provides a possible mechanism for the existence ofequatorial superrotation on Jupiter and Saturn and the lack of superrotation onUranus and Neptune.

A crescente degradação de ecossistemas tornam necessários inúmeros esforços para recuperá-los. A ecologia da restauração é uma ciência que vem crescendo, buscando suporte e apoiando as bases da ecologia teórica. O papel das áreas restauradas na manutenção da biodiversidade é ainda incerto, mas há consenso que estas devem restabelecer os atributos ecológicos. A escolha de bons indicadores ecológicos é crucial para avaliar a evolução dessas áreas. A análise da vegetação é um bom indicador, por ser possível utilizar métodos simples de execução e apresentar respostas rápidas às condições (bióticas e abióticas), fornecendo, por exemplo, informação dos agentes dispersores na área e das características das espécies que compõe a comunidade. Através dessas informações é possível inferir se a área é visitada por animais e como ocorre o processo sucessional. A presente pesquisa consistiu na análise da vegetação de florestas em processo de restauração com idades diferentes. Foram escolhidos plantios com oito e 12 anos e um remanescente florestal. Em cada área foram alocadas 30 parcelas de 10 x 10 m, todos os indivíduos arbustivo-arbóreos (estrato arbóreo) com diâmetro a altura do peito maior ou igual a 10 cm foram amostrados, identificados e tiveram sua altura estimada. O estrato regenerante foi registrado por parcelas de 2 x 10 m alocadas no interior das parcelas (10 x 10m) onde foram amostrados e identificados indivíduos com altura maior ou igual a 50 cm e diâmetro a altura do peito menor que 10 cm. As espécies encontradas foram categorizadas em grupos funcionais (síndromes de dispersão e classes de sucessão) e origem (nativa e exótica). Para o estrato arbóreo e para o regenerante, o ecossistema de referência apresentou maior densidade, riqueza e diversidade. Diferente do ecossistema de referência, os plantios apresentaram muitos indivíduos de espécies de origem exótica, e não apresentaram muitos indivíduos das classes sucessionais clímax. Diante dos resultados talvez sejam necessárias ações de manejo adaptativo, com retirada das espécies que tem potencial invasor e enriquecimento funcional para que a evolução das áreas não seja comprometida. A avaliação da vegetação mostrou-se bom indicativo no estudo da evolução das áreas em processo de restauração. / The growing degradation of ecosystems makes it necessary the adoption of various efforts in order to restore it. Restoring ecology is a science that has been growing, seeking support and providing support to the foundations of theoretical ecology. The role of the restored areas in the maintenance of biodiversity is still uncertain; however there is consensus that they should restore the ecological attributes. The choice of good ecological indicators is crucial in order to assess the evolution of those areas. The analysis of the vegetation is a good indicator, because it enables the use of simple execution methods and because it also presents fast answers to the conditions (biotic and abiotic) providing for example, information about the dispersing agents of the area as well as the characteristics of the species that makes up the community. Through this information, it is possible to infer if the area is visited by animals and how the succession process happens. The current research consists of the analysis of the vegetation of forests in restoring process with different ages. Plantings were chosen between 8 to 12 years and a remnant forest. In each area 30 plots of 10 X 10 m were allocated, all tree species with diameter and breast height higher or the same as 10 cm were shown, identified and had their height estimated. The regenerative component was recorded in plots of 2 X 10 m allocated in the interior of the plots where they were sampled and identified the individuals with height higher than 50 cm and diameter and breast height lower than 10 cm. The species found were categorized in functional groups (dispersion syndrome and restoring guilds). The highest values of density, richness and diversity of arboreal and regeneration layers were found in the reference ecosystem. The forests in process of restoration considered in this work, unlike the reference ecosystem, presented numerous individuous of exotic species, and did not present many late-successional individuous. Results suggest that performing adaptative management actions, such as invasive species removal and functional enrichment, may be necessary for the appropriate evolution of the concerned areas. Evaluation of the vegetation was considered a good indicator to study the development of areas in process of restoration.

L'objectif de cette thèse est l'étude rétrospective du développement de la couronne de quelques grands arbres de la forêt tropicale humide guyanaise. Nous avons retenu plusieurs espèces possédant des tempéraments écologiques, des modèles architecturaux et des cycles phénologiques variés, mais présentant toutes au moins un marqueur morphologique ou anatomique susceptible d'être utilisé dans le cadre d'une analyse rétrospective de l'appareil caulinaire. Nous avons décrit des branches sommitales représentatives de la croissance en hauteur et de la reproduction des individus. Parallèlement, nous avons mis en place un suivi phénologique mensuel afin de pouvoir confronter les résultats issus des descriptions rétrospectives aux résultats du suivi phénologique. L'analyse rétrospective de l'appareil caulinaire permet de reconstituer l'histoire des structures ramifiées sur 10 à 15 cycles de développement en moyenne, mais nous avons pu remonter jusqu'à 40 cycles chez certaines espèces. Les informations recueillies nous renseignent sur l'organisation intrinsèque du cycle phénologique de l'organisme ainsi que sur les modalités de construction et de reproduction de l'espèce. Le fait de pouvoir reconstituer l'histoire des différents méristèmes permet dans certains cas d'approcher les relations trophiques qu'ils entretiennent dans l'espace et dans le temps au sein des structures ramifiées. Finalement, le cadre temporel relatif dans lequel sont replacés les processus développementaux autorise la comparaison d'espèces dont les cycles phénologiques ont des dimensions temporelles absolues différentes dans un cadre temporel relatif identique, dont « l'unité » est l'expression morphologique du cycle phénologique dans son ensemble. L'analyse rétrospective de l'appareil caulinaire des arbres tropicaux apparait donc comme une méthode à la fois souple et robuste, complémentaire des suivis de croissance et de suivis phénologiques plus traditionnels. Les résultats obtenus sont originaux et nouveaux dans le domaine de l'écologie tropicale et ils ouvrent des perspectives intéressantes et prometteuses. / The aim of this thesis is to study retrospectively the crown development of large canopy trees of French Guiana. We choose several species expressing various ecological behaviors, architectural developments and phenologies which had at least one morphological or anatomical marker usable in retrospective analysis. We described well sun exposed branches that were representative of individuals' height-growth and reproduction. Simultaneously, we conducted a monthly phenological survey in order to compare our hypotheses from the retrospective analysis to the phenological data. The retrospective analysis allowed us to reconstruct the last 10 to 15 developmental cycles within the branches in mean, sometimes up to 40 cycles in some species. Data give information on the species' intrinsic phenological organization as on growth modalities and reproduction. We could access to the meristems history within the branches and in some case, we could approach meristems interactions on a trophic level. Finally, we could compare species with various phenological strategies within the same relative temporal frame given that is given by the retrospective analysis. The retrospective analysis appears to be a reliable complementary tool that gives access to new and original results in tropical tree study.

The behaviour of cohesionless soils is known to be influenced by the method of reconstitution. It is generally accepted in the literature that different reconstitution methods produce samples of varying fabric and thus samples of varying behaviour. Very little evidence has been presented to validate this statement. The main aim of this is thesis is firstly to observe the fabric of in situ and reconstituted gold tailings samples and secondly to investigate the difference in behaviour between these samples at the same state. The investigation focused on testing in situ and reconstituted gold tailings samples obtained from 3 positions on a tailings dam; pond, middle beach and upper beach. Laboratory reconstitution methods included moist tamping and slurry deposition. Fabric analysis involved the use of SEM images to classify the observed differences in the fabric of the undisturbed and reconstituted gold tailings samples. A particle interaction model based on the observed fabric was postulated to explain the differences or similarities in behaviour. The scope of behaviour investigated included sedimentation, collapse and swell, consolidation and compressibility, creep, stiffness and shear behaviour. The fabric analysis indicates that differences in the fabric of undisturbed and reconstituted gold tailings samples are visible. Moist tamping produces an aggregated fabric while slurry deposition yields a homogeneous fabric similar to that of the undisturbed samples. Comparison of behaviour indicates that neither moist tamping nor slurry deposition can replicate the behaviour of the undisturbed sample fully. Consolidation and compression is a function of the fabric while friction angle is independent of the fabric. Available shear strength and liquifaction potential is also affected by the preparation method and the resulting fabric. / Thesis (PhD)--University of Pretoria, 2009. / Civil Engineering / PhD / Unrestricted

Předložená diplomová práce se zabývá přípravou, síťováním a fyzikálně-chemickou charakterizací hydrogelů na bázi polysacharidů. Cílem práce bylo vyvinout elastické filmy, které by mohly být použity pro vlhké hojení ran. Teoretická část shrnuje současné způsoby regenerace měkkých tkání a jejích náhradách (ať už se jedná o přírodní nebo syntetické materiály). Zároveň jsou zdůrazněny základní informace o přírodních polysacharidech (chemická struktura, rozpustnost, tepelná a pH stabilita atd.), jejich modifikace a chemické síťování. Experimentální část je zaměřena na modifikaci přírodní gumy Karaya tak, aby transparentní hydrogely měly nastavitelnou hydrolytickou stabilitu. Vzorky byly analyzovány pomocí FTIR, TGA následované vyhodnocením bobtnání a hydrolytické degradace. Z výsledků vyplynulo, že chemická modifikace zvýšila stabilizaci elastického filmu z přírodního polysacharidu ve vodě až na 25 dní. Díky řízené degradaci a vysoké absorpci vody (85 - 96%) jsou tyto nové hydrogely využitelné především pro vlhké hojení ran (např. popálenin).

The USDA Natural Resources Conservation Service (NRCS) implemented the Migratory Bird Habitat Initiative (MBHI) in summer 2010 to provide wetlands for waterbirds inland from the Deepwater Horizon Oil Spill. To evaluate MBHI and associated wetland management practices, I estimated seed and waterbird densities in MBHI and non-managed wetlands in the Mississippi Alluvial Valley (MAV) of Mississippi and Louisiana. Although not statistically different, wetlands enrolled in MBHI contained 1.26 and 1.53 times more seed biomass and seeds consumed by waterfowl than non-managed wetlands, respectively. I also detected 3 times more dabbling ducks and all ducks combined on MBHI wetlands. When I combined density data for all waterbird species, MBHI wetlands contained more than 2 times as many birds than control wetlands. Management via MBHI increased waterbird and potential food abundances, suggesting NRCS consider sustaining MBHI and provide financial incentives to landowners for management of wetlands in the MAV and United States.

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